This invention relates to devices which dry hair both by blowing water off it and by evaporation.
On the market today are many commerical products used in human hair drying which comprise a blower and means for adjusting its speed and the temperature of the discharge air. Selinger, U.S. Pat. No. 3,430,353, improved the efficiency of such a hair dryer by having its discharge air recirculate over the hair. While saving on the thermal energy required to heat the recycled air, much of the energy saved by Selinger's device is consumed in evaporating the water present in the recycled air which is saturated with moisture.
Earlier, Marty, U.S. Pat. No. 2,827,060, utilized a valve to divert the heated air flow from a hari drier. With Marty's valve, part of the flow of the heated air can be diverted to a nozzle for rapid hair drying or to the brush for use in styling the hair.
Solar et. al., U.S. Pat. No. 4,097,722; Springer, U.S. Pat. No. 4,232,454; and Da Silva, U.S. Pat. No. 4,526,623, all realized the benefits of controlling the rate at which air is discharged from their devices.
While each of the hair driers in the cited prior art has a control with which one can vary the air discharge rate, each of these drier heats the air with the use of an electric heating element. Unfortunately, the use of such an element can overheat a dog's skin which is sensitive to high temperatures.
All the prior art references mentioned above realized an improvement to a hair drying apparatus by having controls with which to vary the air discharge rate. However, the means for heating, in each instance, was by the use of a electrical heating unit. For this and other reasons, hand-held driers such as those designed for blow drying human hair are not suitable for use with pets. Not only can such drier get an animal's skin too hot but also having an electric applicance so close to the animal is dangerous. Especially in the case of dogs, whose nature is to shake themselves to rid their fur of excess moisture, the water, when hurled off, can damage a hand-held drier and pose a potential electric shock hazard both to the animal and to the operator.